1. Technical Field
The present invention relates to an imaging little fish management device capable of individually observing or imaging a plurality of little fishes and a little fish imaging plate used in the same.
2. Related Art
The use of zebrafishes has gained attention in a medical field and a pharmacy field. As an example, after eggs of gene-injected zebrafishes are hatched and bred, the shapes and the like of the adult fishes are visually checked or imaged. As another example, after immature zebrafishes are bred while a specific medical agent is introduced into their living water system, a fish shape or a partial tissue shape is visually checked or imaged. Since the zebrafishes are small and grow fast, the zebrafishes can be highly efficiently used as a plurality of kinds of subjects. Further, an ethical issue on animals is also relieved.
In order to observe or image the zebrafishes, an imaging device such as a microscope or an electronic imaging device is used. However, since the zebrafishes are very small, there has been a problem in sequential observation or imaging of the plurality of zebrafishes, which burdens a skilled worker with a heavy workload.
In order to highly efficiently image specific regions of the plurality of zebrafishes, an imaging plate which includes a well array having wells formed in a matrix shape and depressed is used. The zebrafishes are separately disposed in the plurality of wells by using a tool such as a pipette or a pincette. In order to suppress the deterioration of zebrafish living conditions, it is favorable that some water be held in each well.
In imaging work including observation or imaging, it is preferable that illumination light irradiation be performed from the bottom surface side of the imaging plate and reflected light or fluorescence from the zebrafishes is sent from the bottom surface side of the imaging plate to an imaging system. The imaging plate is shifted by the pitch of one well in a direction perpendicular to an optical axis of the imaging system. Accordingly, the zebrafish inside each well is highly efficiently observed or imaged.
In order to satisfactorily image a specific region of each zebrafish, it is preferable to lay the zebrafish on a center portion of a bottom surface of each well. Further, in order to simplify image processing, it is preferable to arrange the zebrafishes such that the longitudinal direction from the head to the tail of each zebrafish (hereinafter, referred to as a head-to-tail direction) becomes the same direction. However, there has been a problem in work of correcting a position and posture to lay each zebrafish on the center portion of the bottom surface of the well while each zebrafish is arranged in the same direction, which is very troublesome and easily damages the zebrafishes.
In order to solve this problem, US 2007/0178012 and JP 2014-169951 A (published on Sep. 8, 2014 by HASHIMOTO ELECTRONIC INDUSTRY CO., LTD and the like) adopt a side viewing optical system capable of imaging zebrafishes from the lateral directions of wells. According to the side viewing optical system, the zebrafishes which are not lying can be satisfactorily viewed from the sides thereof. However, since the side viewing optical system needs a reflection surface for deflecting an optical axis, a structure of an imaging plate becomes complex. Further, it has been found that there is a problem of a degraded image due to dirt or the like on the reflection surface.
Further, when the zebrafishes as subjects are sequentially put into the wells of the imaging plate by using a manipulation tool such as a pipette or a pincette, there has been a case where the zebrafishes are damaged. Moreover, there has been a case where contamination unfavorable for the zebrafishes happens through the manipulation tool.
In order to solve this problem, it is desirable to grow the zebrafishes while separately putting the zebrafishes into the wells at the immature stage and thereafter giving a medical agent and the like necessary for each immature fish. However, management of water including treatment of feces becomes essential for breeding of the zebrafishes. Further, it becomes essential to put an anesthetic solution during imaging and to replace breeding water after the imaging. In the related art, an imaging plate capable of managing water in this way is not known.